I’ve had a number of readers email me to ask how to get rid of gnats in the house. It’s a good question — and I can’t stand the thought of those pesky plant gnats.
After doing some research, however, I’ve discovered that over watering is a huge factor in creating the problem. The gnats lay eggs and reproduce in moist soil. So the No. 1 one way to prevent plant gnats is to not over water. If you already have them in your soil, the easiest way to get rid of them is to re-pot your plants in healthy, fresh soil.
If you’d rather not re-pot, you can’t figure out a good watering schedule or you just can’t seem to get rid of the gnats, here are a few other things you can try.
Solution 1: Soap and vinegar
When watering your plants, mix 1 tablespoon of soap and 1 teaspoon of white vinegar into the water. Water with this solution every other watering. (Source)
Solution 2: Gnatrol
There is a product on the market called Gnatrol. It’s a natural bacillus toxin that can be added to the water when you water your plants. Gnatrol will kill the larvae, but the plants have to be treated several times, about six weeks total. This is a very effective method as long as you are not also fertilizing. (Source)
Solution 3: Sticky Stakes
Sticky Stakes are an inexpensive product that catch the flying gnats. This is a good solution for gnats that have already hatched and it will allow you time to let the soil dry out and treat it to get rid of the larvae. (Source)
Solution 4: Moth balls
Moth balls are another way to get rid of gnats. Place one to two moth balls in a 12-inch pot and it should get rid of the gnats. The moth balls should also prevent other pesky critters from being attracted to your plant. (Source) I do not recommend this solution if you have small children in your home. You don’t want a small child to mistake a moth ball for a piece of candy!
Solution 5: Horticultural Sand
The flying gnats lay their eggs in the soil and the cycle starts all over again. Stop this cycle by applying a 1/8″ layer of horticulture sand to the top of the soil of your plants; the larvae/pupae can’t hatch out of the soil and the flying gnats can’t lay their eggs in the soil – it stops the cycle, and best ofall nothing toxic and no re-applying every 7 days! (Source: a local nursery, Wyntour Gardens)
I hope these solutions will help you to get rid of your plant gnats so you can fill your house with beautiful plants and not be annoyed by the gnats!
We have tons of house plants and found that the gnats were a huge problem in our new house. We simply bought a small bug zapper, which comes on automatically every evening. Whatever gnats are hatched during the day die by night. We haven’t had another problem since installing the zapper.
Where did you buy the small zapper?
I put vinegar and a few drops of dish soap, mixed in a small medicine cup. Fill the cup to the top, almost overflowing. They crawl down for a drink and drown. Read in on a blog and it works for the gnat from bananas.
Thanks for the suggestions. I overwater my plants and then I get gnats. I’m going to use your water mixture to try it.
Thanks for the suggestions. I overwater my plants and then I get gnats. I’m going to use your water mixture to try it. Thanks 🙂
I’ve used the soap before….but I’ve never tried vinegar!
Thanks so much for all the great tips!
blessings,
karianne
Great tips! I HATE gnats! Going to try the soap and vinegar trick.
Heather
Thanks for sharing Anna! Great tips!
Ah…. always have wondered why I see mothballs in plants sometimes…now I know! Thanks for all these helpful tips!
Great tips, thanks so much!
Gnats are not the problem, they don’t live a long time. The problem is the larva in the soil, you have to kill those. I don’t believe any home remedy will work. Not sure about the moth balls, don’t know what it would do to the roots of the plant and it might stink up the house. Nursery’s sells a product called Hi-Yield Systemic Insect Granules that works. You dig it in the top inch of the soil and water lightly. That kills the larva. I got my gnats in my Miracle Grow potting soil. I was told they have a huge gnat problem in their plant.
I thought about that with miracle grow plant dirt. Also i found i have a problem with mushrooms with miracle grow plant dirt. Anybody else with that problem. Please assist. Thanks
Just curious as to what the water ratio is to the soap and vinegar
Hi, Jada! I’m Anna’s assistant, Bethany. You can start with a ratio of 2/3 water to 1/3 vinegar/soap mixture, and then increase the vinegar/soap mixture slightly if you think it needs it. Hope that helps!
Dear Anna’s assistant, Bethany,
Do you put the moth balls into the plant’s pot or do you need to put out a 12″ bowl just for the 1 or 2 moth balls?
I think you could put them directly in the pot.
We have a cow pasture behind our house that they spread chicken litter on. It seems like gnats are coming from that. We also have an abundance of flies! Was wondering if you have any recommendations.
Hi, Debra! I’m Anna’s assistant, Bethany. Anna’s sister also lives on a farm and has major issues with flies and has tried everything to no avail. She has found some creative ideas online so you may want to try Google. Sorry we couldn’t be more help!
There are a couple of solutions for eradicating and controlling fungus gnats that I have found to be effective, reliable and best of all, completely non-toxic and safe for use in house around pets and children. The first is to use Bacillus thuringiensis or BTi. I buy the mosquito bits brand and they release a bacteria fed on by larvae of fungus gnats that kills larvae. Also, I recommend purchasing beneficial nematodes. They are live organisms that live in soil and are applied when watering. The beneficial nematodes will seek out the larvae and kill them. With a combination of yellow sticky strips, mosquito bits, and beneficial nematodes, it’s completely possible to completely eradicate the fungus gnats. I always treat new houseplants and soil asap to prevent spread. You can get both products at the big box garden stores or a mail order company called Arbico organics. Any good quality plant nursery should also know about and sell these products. Good luck, fungus gnats are common and very irritating!!
Your advice about using moth balls needs to come with more pre-caution. Moth ball can seriously impair indoor air quality. In fact, the odor of mothballs can be detected at a few parts per billion in the air. (One part per billion is about several drops of water in an Olympic-size swimming pool.) In large quantities can lead to headaches, nausea, vomiting, diarrhea and then some. Some moth balls contain Naphthalene, which is possibly a carcinogen and can cause cancer. This seems like an extreme last resort to use and if you’re going to advise using this at all, it should be your very last recommendation and you should include this information.